1. Field of the Invention
The invention generally relates to a semiconductor module structure and method of forming the semiconductor module structure and, more particularly, to a thermal paste containment system incorporated into a semiconductor module structure and a method for forming the thermal paste containment system within the semiconductor module.
2. Description of the Related Art
Many structures are known for removing or dissipating heat from semiconductor dies. In one structure a die is mounted on a substrate and a flat cooling plate or flat lid is placed over a die. The gap between the die and the lid are filled in with a thermal compound (i.e., thermal grease, thermal paste, thermal gel, etc.), which promotes heat conduction between the lid and the die. Controlling the coverage of the thermal paste over the die to ensure that the gap is filled in is critical for heat removal. Thermal cycling of the semiconductor module can result in the expansion and contraction of the lid and substrate. This expansion and contraction can result in pumping of the thermal compound such that the thermal compound moves out of the interface between the die and the lid, leaving air pockets and reducing effective heat removal. This disclosure presents a method and structure for containing the thermal compound between the die and lid to limit the effects of thermal compound pumping.